Color photography



Feb, 6, 1923.

J. G CAPSTAFFET AL,

COLOR PHOTOGRAPHY.

FILED MAR, 25,1921.

WITNESS g -l1 Patented F eh. 6, 1923.

UNITED STATES 1,444,329 ATENT OFFICE.

363E313 G. GAPSTAFF AND NEWTON B. GEE EN, OF ROCHESTER, NEW YORK, ASSIGNORS TO 'IIHAN KODAK GOMPANY, OF ROCHESTER, YORK, A CORPORATION OF YORK.

COLOR PHOTOGRE Application filed March 25, 1921.

immit mag/concern.

Be it known that we, JOHN G. CAPSTAFF and llniwron B. GREEN, subject of the King of Great Britain, citizen of the United States of America, respectively, residing at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Color Photography, of which the following is a full, clear, and exact specification.

, This invention relates to color photography and more particularly to a process involving the use of a transparent support or base upon the opposite sides of which are registered complementary color images.

in the patent to Capstatf No. 1,196,080, August 2, 1916, the steps of such\a process are outlined. it has been found, when the registering images upon the opposite sides of a transparentsupport have been dyed in complenien tary colors, to be a delicate operation to balance properly the intensity of the colors so as to produce satisfactory repro' ductions of the original objects. The object of this invention is to modify this color balance or ratio after dyeing so as to correct any apparent errors.

in the process as outlined in the above mentioned patent, gelatinc layers upon opposite surfaces of the support are differen tially tanned in accordance with the photographic images, and then submitted to complementary dye baths. After dyeing, the emulsion is submitted to an acid alum bath which, we believe, precipitates or fixes the dye in place in the gelatine. The registering images made in acco dance with the process mentioned, therefore, comprise as we believe. dye images precipitated in place in the gelatine by the action of this bath. in stating the nature of the dye image, we do not wish to bind ourselves to any theory that may possib y be disproved at some future time. Vi e have discovered that color images made in the manner heretofore described can be treated as herein fully set forth and we shall describe various equivalent steps that may be used. It is possible that in addition to a precipitated dye image there may be some coml'iination between the dye'and the colloid of the emulsion, but. neither the es tabiishm nor disproof of such a relation would a he facts which we have discolor ratio, i. e., the relative coloring upon the opposite sur Serial No. 455,706.

faces, is largely a matter for the judgement of the operator, andafter the record is completed, it has hitherto been possible to correct this color ratio only by entirely decolo izing one of the emulsions and resubmitting it to a dye bath. This is true also of other processes in which the images are composed of mordanted dyes; i. e., dyes adsorbed to particles in the gelatine layers. We have discovered. however, that it is possible to correct an imperfect. color ratio. This incorrect ratio necessarily means that one side is more intense than the other, and it is possible, by submitting the too intensely colored side to a bath which tends to release the dye, to reduce the intens..y of its color to a point where it will properly balance the color oi the other side.

in order to poi t out more in which this method reference wi l now be mace to the accompanying drawings in which fully one way be practiced,

4 the same refer euce characters refer throughout to the same parts, an 1? which Fig. plan of an apparatus which may be used;

' Fig. 2 s a front elevation thereof;

Fig, shows the relation of two of the parts; and v Fig is a erspec-tive detailed view of p the gait for the film.

Upon atable l is supported on axis 2 a rotatable reel 3 carrying va supply rol of motion pict 4, the film, having been so treated as to bear complementary color images of the type described. A take-up reel 5 is driven by the motor 6 which also drives a. butling roller 7. This butting roller has felt surfaces and is adjustable vertically to three positions, being controlled by means of a pedal 8, two positions of the pedal being shown in dotted lines. The roller is shown in its uppermost position in Fig. The film 4 passes in front of an illuminating box 9 and the operator inspects it as it passes the window of this box, judging whether or not the color ratio is correct. The film normally passes from said inspection window to the take-up reel, being guided by rollers 10 and passing through a. drying cabinet 11. The roller 2 is normally in middle position during such action and the film passes untwisted directly over the inspection window to the drying chamber s indicate l dotted During su image to dissolve the 1 1m in one direction or the color intensity the roller and the pressure 7 is atank or bath 16 in which is a solution which will be more fullydescribed hereafter. On the edgeof the tank 16 is sup-1 ported a smaller roller 17 which is carried by a pivoted arm 18', and is pressed inwardly by a spring 19. The roller 7 may e lowered into the tank,

felt will be saturated with the solution of the bath. The roller 17 acts upon it, how-. ever, to remove all .excess moisture so that the felt is rendered moistbut not too wet. Above the roller 7 there is supported a pressure pad 20 which is spring-pressed upwardly but which may be; pressed down by the pedal 21. l

Should, in the judgment of the operator, one side be too intensely colored, he will rasp one of the handles 15 and turn the ii the other so that the more intensely colored surface will be directed downwardly; at the same time he will, through the agency of the pedals, cause the pressure pad 20 to move downwardly and the roller 7 to move up, so that the roller which is constantly driven by the motonwill bufl the lowersurface of the film. The solution with which the roller is dampened has the effect of releasing from the image some of the dye so as to lessen of that surface of the film The degree of this action may be controlled by the degree of pressure between by the degree of dampness of the roller. If the image is one formed .-by the processes outlined above, and consists of dye precipitated or fixed in place by the acid alum bath, we have found the following. correcting or buffing bath to be a. useful one: denatured alcohol (90%), 100 parts; ammonia (.880),

1 part.

Theammonia. acts upon the dye fixed precipitated dye and release the dye. As the buffer is merely damp and its action is controlled, the amount of dye released is within the control of the o erator. Other alkali baths may be used. Wi e prefer ammonia, however, because this is volatile and leaves on the film no objectionable coatin as might be the case with some alkali sol utions. The alcohol is not essential but is used to insure quick drying. Since the alcohol and ammonia rate readily and since, moreo er, the surface of the film is merely damp, drying in the open air may be sufficient, but I have shown a drying box 11 to insure the drying of the film before it is again rolledup.

being controlled by the pedal, and when thus lowered and raised again, the

pad above it, and

both evapoe issa trativdlyand the carrying outj ofour process is in no .wa nism. Fort is reason, the showing and description havebeen simplified. as far as is.

consistent w1th an understanding of the principles of the invention. of fact, We have found it readily possible merely to pass the film from a supply to a take-up reel past an inspection window and to rub one or the other side of the film with a cloth dampened with the solution, the distance between the reels being made sufficient to dry the film, as it passes through the air. The corrected'imag'e may be again examined before being wound up. Itis within the scope of our invention to apply this process to dye images formed in other manners, in which case it would, of course, be necessary to adapt the solution to the characterof the image so that it would act upon it to re lease the dye.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. The method of correcting the color ratio of a diapositive consisting of a trans parent base with different color records in register upon which comprises submitting one face only thereof, to the action of a solution which will lessen its color intensity.

2. The method of correcting the color ratio of a diapositive consisting of a transparent support with registering complementary color records upon the opposite faces thereof, each record comprising loid layer in which is a dye image, which method consists in submitting that surface which is too intensely colored to the controlled action of a solution which will release the dye.

3. The method of correcting the color .base with reg1stering complementary color records upon the opposite surfaces thereof. each color record comprising a dyed colloid film in which the dye has been fixed by an acid, which method consists in submitting that surface which is too intensely colored to the controlled action of an alkali solutionwhich will dissolve and release the dye;

5. The method of correcting the color ratio of a diapositive consisting of a transparent It is to be understood that the particular. mechanism illustrated above is purely illussupport with gelatine layers upon the op posite surfaces thereof, in which there are dependent upon this -mecha- As a matter the opposite faces thereof,-

registering imageg ronsistimgof d ven of (Olllllltllltllttly rolor preeipitated hr the :u tion (it an arid alum hath, \Ylllt'l] method ronsists ol suhmittine' the. too intenael r rolored image to the eontrolled aetion ot an ammonia solution.

3. In a proeess of making (-olor motion picture reeordx. eomprising the formation in (olloid layers upon oppositesides oi a train parent Support of registered eompleinentar eolored dye images. the steps of ins-petting sueh registered dye images to determine whit-h. it either. of the images is too intensely eolored and then auhmittin; the too intensely eolored image to the controlled aetion of a solution that will release the dye.

7. in a process oi making eolor motion picture records. eon'iprising the formation in colloid layers upon opposite sides of a transparent support of registered images eon- .viSt'lllQ oi" dyes ol' wanpleu'ientar v eolor precipitated hy the aetiou M an arid. the steps ol' iuspeetingg' sin-h registered dye images by transmitted light to determine whielu it either. ol the images is too intensel eolored and then submitting the too intensely rolored image to the 'eontrolkal aetion ot' a solution that will dissolve and release the dye.

5 The method of eorreetinf the color ratio ot a diapositire (TOIlSlstillg ot' a transparent hase with dye images in register upon he opposite fares thereof. whieh romprises suhmuting one tare only thereof to the aetion of a. volatile solution Whirl] will release the dye. v

Signed at Roel-iester. New York. this 21st day of Marl-h. 1921.

JOHN G. (A'PSTAFPX NEWTON B. GREEN. 

